This invention relates to certain polyamide copolymers prepared from unbranched aliphatic dicarboxylic acids and a diamine mixture. More particularly, this invention relates to such polyamide copolymers which are useful as melt adhesives, especially for textiles.
It is known that certain polyamides can be applied as melt adhesives for textiles. The use of a polyamide for this purpose requires a good washing resistance to warm washing suds and a special melting characteristic that allows for processing in a technical important temperature range of about 120.degree.-160.degree. C.
It is also known that the melting behavior of a polyamide can be adjusted by copolymerization.
A further demand for textile melt adhesives is a high water absorption so that the vapor diffusion is not affected in the glued materials.
Up to the present, all polyamides, which have been used as textile melt adhesives, have shown that they tend in powder form to baking together, especially when they contain aminocarbonic acids. Therefore additives are regularly mixed to these powders in order to improve the trickling ability. If the aminocarbonic acids are omitted at mean average molecular weight (Mn) the baking is decreased, but the range of melting temperature is so small, that the polyamide cannot be processed in the common machines.
There is a need to transfer the good effect obtained by use of branched diamines to compounds free of amino acid.